Internal-combustion engine.



H. R. RICARDO & H. A. HETHERINGTON.

INTERNAL COMBUSTION ENGINE. APPLICATION FILED FEB. 1, 19151 Patented 113,130, 1915.

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H. R. RICARDO & H. A. HBTHBBINGTON.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED FEB.1,1916,

313x511? Patented Mar. 915.

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RALZPH RTGARIDO, F LONDUN, AND HENRY ANSTRUTI-IER HETHIEE-TNGTQN, 6F

: r, ENGLAND.

INTERNAL-COMBUSTIUN ENGINE.

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Specification of Letters Patent.

Patented. Mar. 3th, ttltt'd.

application-filed February 1, 1915. Serial No. 5,560.

To (lilac/1.0m. it may concern:

Be it known that we, HARRY RALPH liticanno and HENRY Ansrno'rnnn Hn'rnna- INGTON, subjects of the King of England, and residing, respectively, at London, in England, and Bytieet, Surrey, in England, have invented a certain new and useful Improvement in Internal-Combustion Engines, of which the following is a specification.

This invention relates to internal combustion engines operating on the two-stroke cycle and more particularly those of the type whichcomprise two working cylinders disposed side by side with their inner ends in free communication.

The present improvements have for their object to combine means whereby the reciprocating parts are more satisfactorily balanced than heretofore with arrangements to enable the crank casing to be used more etliciently as a pump chamber for compressingthe combustible mixture and introducing it into the. working cylinders.

According to this invention a third cylinder of larger diameter is disposed opposite to the two working cylinders the ends of all three cylinders opening into a closed crank chamber. The pistons of these three cylinders are so connected to a common crank shaft that the piston in the third. cylinder is reciprocated oppositely to the pistons in the working cylinders the latter being substantially balanced by the third piston. All three pistons act as pumps and by their simultaneous outward movement first draw into the crank chamber the combustible mixture subsequently compressing it therein by their simultaneous inward motion.

Tn the preferred construction three sepa rate crank pins are provided for the connecting rods of the three pistons, the crank pins for the pistons of the working cylinders being conveniently disposed on either side of a crank pin by which the third piston is reciprocated. The two crank pins of the working pistons are so relatively placed circumferentially about the shaft that one has a slight lead over the other.

The construction is such that in operation as all three pistons simultaneously move outward a partial vacuum is formed in the crank chamber until the inlet ports for the combustible mixture which are'formed' in or toward the end of one of the working cylinders are uncovered. The combustible mixture is then drawn in and by the simultaneous inward movement of all three pistons 1s compressed in the crank chamber unt l. such time as the inlet ports formed in the length of the wall of oneof the workmg cylinders are uncovered. The exhaust ports are formed in the length of the wall of the second working cylinder whose piston is connected to the crank pin having the slight lead. As a result of this lead these exhaust ports are opened slightly be fore the inlet ports in the first cylinderare uncovered. Thus the exhaust begins to es cape from the working cylinders through the second cylinder before the first charge enters the first cylinder from the crank chamber, this charge finding its way from the crank chamber through one or more passages formed around the end of the first working cylinder.

In the accompanying drawings, Figure 1 1s a vertical sectional elevation through an engine constructed in accordance with this invention the section being taken on the,

plane in which lie the axes of all three cylinders. Fig. 2 is a vertical section on the line 22 of Fig. 1.

Like letters indicate like parts throughout the drawings.

The twin working cylinders A and B are formed and arranged side by side as clearly shown in Fig. 1 with their axes parallel and their inner ends in free communication through the passage C. The ends of these cylinders open into a closed crank chamber D to which the cylinders are rigidly connected. On the side of the crank chamber opposite to the cylinders A and B is a third cylinder E whose diameter is larger than that of either of the cylinders A and B.

The inner end of this cylinder E opens into the crank chamber. The crank shaft F has three crank pins F, F F The pins F, F are connected by connecting rods to trunk pistons A, B respectively in the cylinders A and B. The crank pin F is connected by a connecting rod to a piston E in the cylinder E. The crank pin F has a slight lead with respect to the crank pin F as shown in Fig. 2. In the engine illustrated in the accompanying drawings by way of example the crank pin F is oppositely situated with respect to the crank pins F, F so that the angle between the crank pin F and eachof the crank pins F and F is the same and almost 180 being short of this amount by one half the amount of lead that the crank pin F has over the crank pin F. In the example illustrated this lead amounts to 20 so that the angle between the crank pin F and each of the crank pins F, F is 170.

In the wall of the cylinder A is formed a series of inlet ports Or so disposed that they are uncovered by the piston A when it is near the end of its outward stroke. A corresponding series of exhaust ports H is formed in the wall of the cylinder B these ports also being so placed as to be uncovered by the piston B shortly before it completes its outstroke. The inlet ports G open into an annular chamber G formed around the outer end of the cylinder A. The end of this chamber opens at G into the crank chamber D. The exhaust ports H lead into an annular chamber H which communicates with the exhaust pipe H A second series of ports J is formed in the wall of the cylinder B beyond the exhaust ports H and in such a position that these ports J will be uncovered by the piston B just before it completed its instroke. The ports J open into an annular chamber J which communicates at J 2 with the induction pipe from the carbureter. Owing to the proximity of the annular exhaust chamber H to the annular induction chamber J the charge entering the latter is warmed by the exhaust products. A sparking plug is inserted in the opening O leading into the passage 0 between the ends of the cylinders A and B and the opening C may conveniently be utilized for a compression tap.

In operation-all three pistons simultaneously move away from the crank in so doing forming a partial vacuum in the crank case D. Just before the piston B which has the lead completes its instroke the ports J are uncovered and combustible mixture is forthwith drawn into the crank case. On the succeeding outstroke of all three pistons which takes place simultaneously this charge of combustible mixture is compressed until the piston A has nearly completed its outstroke. The ports G are then uncovered and the compressed charge at once enters the cylinder A- passing to the inlet ports through the annular-chamber G. The charge sweeps through the passage G into the cylinder'B driving before it the last of the exhaust products from the preceding charge which are finding their way out of the cylinder B through the ports H which were uncovered just before the piston B completed its 'outstroke. Owing to the lead which the piston B has over the piston A" the exhaust ports are uncovered in advance of the uncovering of the inlet ports G and consequently also the exhaust ports H are covered on the succeeding instroke of the piston B slightly before the inlet port G are covered on the instroke of the piston A. The instroke of all three pistons takes place simultaneously and the charge is compressed in the working cylinders A, B and the communicating passage C. The cycle as described is now recommencing the fresh charge being drawn into the crank chambaby the partial vacuum that has been created, this charge being compressed in the crank chamber after the main charge in the cylinders A and B has been fired and while the pistons A, B are performing their outstroke.

The upper side of the piston E is conveniently formed as a trough E which serves to contain lubricating oil. The crank pins F, F approach this trough so closely that the lubricant in the trough will be thrown about the crank case sufiiciently to lubricate the parts of the engine. The outer end of the cylinder E is conveniently provided with an opening E as the side of the piston which faces this end of the cylinder has no work to do. The opening may be closed gith a convenient light casing to exclude ust.

The balancing effect obtained by the third piston can be regulated when constructing the engine by determining the dimensions of the third cylinder and its accompanying piston with reference to the combined weights of the working pistons.

In the engine shown in the accompanying drawings'and described above the axes of all three cylinders lie in one plane, this being the preferred arrangement. In some cases however, it may be desirable to arrange the relative positions of the cylinders slightly differently. Thus for example while the two working cylinders A and B may lie with their axes in one plane which plane also includes the axis of the crank shaft, the third cylinder E may be thrown slightly out of this plane to one side or the other. The relative positions of the crank pins may also be varied for example to accord with the relative positions in which the cylinders are disposed. The extent of the lead given to one of the working pistons over the other may be modified or dispensed with as found desirable.

The engine as illustrated in the accompanying drawings is air-cooled but may be constructed for water cooling. The details of construction of the engine may be varied generally to suit requirements. The engine as illustrated may be considered to constitute a unit and two or more of such units may be combined on one and the same crank shaft. It is desirable that the crank chamber' of each unit be separated from the crank chamber of another unit but in such cases the arrangement may be varied as found convenient.

a meat-ea bustion engine to employ three cylinders of which two were disposed side by side and the third of larger diameter opposite to them, the pistons beingconnected to three cranks so arranged that a balancing effect was obtained. In that case however all three cylinders were working cylinders and operated on the four-stroke cycle and neither of the pistons acted as a pump in conjunction with the crank case as in the present invention.

What we claim as our invention and de sire to secure by Letters Patent is 11. In an internal combustion engine operating on the two stroke cycle the combination of a closed crank chamber, two working cylinders mounted side by side onand each opening as to one end into thejcrankchamher, and as to the other end closed except for a free communication between the two cylinders, a third cylinder open at both ends and mounted on the crank chamber oppositely with relation to the working cylinders, pistons in the working cylinders operatively connected to like cranks on a shaft in the crank chamber, a piston in the third cylinder operatively connected to a crank oppositely disposed on the shaft with relation to the other cranks, ports in the wall of one working cylinder for the admission of the combustible mixture thereto, ports in the wall of the other working cylinder for the passage thence of the exhaust products, and ports through which combustible mixture can be drawn into the crank chamber as set forth.

2. ln an internal combustion engine operating on the two-stroke cycle the combination of a closed crank chamber, two working cylinders mounted side by side on and each opening as to one end into the crank chamber and as to the other end closed except for a free communication between the two cylinders, a third cylinder open at both ends and mounted on the crank chamber oppositely with relation to the working cylinders, pistons in the working cylinders operatively connected to like cranks'on a shaft in the crank chamber, a piston in the third cylinder operatively connected to a crank oppositely disposed on the shaft with relation to the other cranks, ports in the wall of one working cylinder communicating with the crank chamber, a series of ports in the wall of the other working cylinder communicating with the exhaust passage, and a second series of ports in the wall of this working cylinder toward its open end com-v municating with the fuel supply passage, all the ports in the two working cylinders being controlled by the pistons in these cylinders as set forth.

- 3. In an internal combustion engine operating on the two-stroke cycle the combination of a closed crank chamber, two working cylinders having similar diameters mounted side by side on and'each opening as to one end into the crank chamber and asto the other closed except for a free coinnnr nication between the two cylinders, a third cylinder of larger diameter than either of the working cyhnders open at both ends and mounted on the crank chamber oppositely with relation to the working cylinders, pistons in the Working cylinders operatively connected to like cranks on a shaft in the crank chamber, a piston in the third cylin' der of such dimensions as to equal approxiniately the combined weights of the two working pistons this third piston being operatively connected to a crank oppositely disposed on the shaft with relation to the other cranks, ports in the wall of one working cylinder for the admission of the com bustible mixture thereto, ports in the wall of the other working cylinder. for the passage thence of the exhaust products, and ports through which combustible'mixture can be drawn into the crank chamber as set forth.

4. in an internal combustion'engine op erating on the two-stroke cycle the combination of a closed crank chamber, a crank shaft, two working cylinders having similar diameters mounted side by side on andeach opening as to one end into the crank chamber and as to the other closed except for a free communication between the two cylinders, a third cylinder of larger vdiameter",

than either of the working cylinders open at cylinders, all three cylinders being arranged with their axes in one plane which cuts the axis of the crank shaft, pistons in the working cylinders operatively connected to like cranks on the shaft in the crank chamber, a piston in the third cylinder of such dimensions as to equal approximately the combined weights of the two working pistons this third piston being operatively connected to a crank oppositely disposed on the shaft with relation to the other cranks, ports in the wall of one working cylinder communieating with the crank chamber, a series of ports in the wall of the other working cylinder communicating with the exhaust passage, and a second series of ports in the wall of this working cylinder toward its open end communicating with the fuel supply passage, all the ports in the two working cylinders being controlled by the piston in these cylinders as set forth.

5. In an internal combustion engine operating on the two-stroke cycle the combination of a closed crank chamber, two working cylinders mounted side by side on and each opening as to one end into the crank chamber and-as to the other end closed except for a free communication between the lltl) two cylinders, a third cylinder open at both ends and mounted on the crank chamber opgositely with relation to the working cy'liners, pistons in the working cylinders operatively connected to like cranks on a shaft in the crank chamber, a piston in the third cylinder operatively connected to a crank oppositely disposed on the shaft with relation to the other cranks, ports in the wall of one working cylinder communicating with the crank chamber, an annular exhaust passage surrounding the wall of the other working cylinder, a series of ports in the wall of this working cylinder communicating with the annular exhaust passage, a second annular exhaust passage surrounding the wall of this cylinder toward its open end but adj acent to the first annular exhaust passage this second annular exhaust passage eommuni eating with a source of fuel supply, and a second series ofparts in the wall of this working cylinder communicating with the annular fuel supply passage, all the ports in the two working cylinders being controlled by the pistons in these cylinders as set forth.

6. In an internal combustion engine operating on the two-stroke cycle the combination of a closed crank chamber constituting a fuel pump chamber, a three throw crank shaft in this chamber two of the cranks being similarly placed on the shaft while the third is placed between them along the shaft and oppositely disposed with relation to them, two working cylinders mounted side by side on and each opening as to one end into the crank chamher and as to the other end closed except for a free communication between the two cylinders, a third cylinder open at both ends and mounted on the crank chamber oppositely with relation to the working cylinders, pistons in the working cylinders operatively connected to the like cranks on the crank shaft, a piston in the third cylinder operatively connected to the third intermediate crank on the shaft, all three pistons operating in conjunction with the crank chamber as pumps, ports in the 'wall of one working cylinder communicating with the crank chamber, a series of ports in the wall of the other working cylinder communicating with an exhaust passage, and a second series of ports in the wall of this working cylinder toward its open end communicating with a fuel supply passage and serving to admit fuel from this passage to the crank chamber, all the ports in the two working cylinders being controlled by the pistons in these cylinders as set forth.

In testimony whereof we have signed our names to this specification in. the presence of two subscribing witnesses.

HARRY RALPH RICARDO. HENRY ANSTRUTHER HETIIERINGTON.

Witnesses:

EUSTACE HENRY BARKER, FREDERICK SKILTON. 

